<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html lang="en">
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="created" content="2018-10-23T06:18:10.521000000">
    <meta name="changed" content="2018-10-23T06:18:42.262000000">
    <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <meta http-equiv="Content-Language" content="en">
    <title>
      Generating a circuit
    </title>
    <link rel="stylesheet" type="text/css" href="../../style.css">
  </head>
  <body>
    <div class="maindiv">
      <h1>
        Generating a circuit
      </h1>
      <p>
        The <b class="button">Build Circuit</b> button will construct a circuit whose gates correspond to the currently chosen expressions for each output. The circuit's inputs and outputs will be displayed in top-down order corresponding to how they appear under the Inputs and Outputs tabs. Generally speaking, the constructed circuit will be attractive; and, indeed, one application of Logisim's Combinational Analysis module is to beautify poorly drawn circuits. Still, as with any automatic formatting, it will not express the structural details that a human-drawn circuit would.
      </p>
      <p align="center">
        <img class="notscal" src="../../../../img-guide/analyze-circuit.png" alt="#########">
      </p>
      <p>
        When you click the <b class="button">Build Circuit</b> button, a dialog box will appear prompting you to choose which project where you want the circuit and the name you wish to give it.
      </p>
      <p align="center">
        <img class="notscal"  src="../../../img-guide/analyze-build.png" alt="#########">
      </p>
      <p>
        If you type the name of an existing circuit, then that circuit will be replaced (after Logisim prompts you to confirm that you really want to do this).
      </p>
      <p>
        The <b class=propertie>Build Circuit</b> dialog includes two options.
      </p>
      <ul>
        <li>The <b class="button">Use Two-Input Gates Only</b> option specifies that you want all gates constructed to have two inputs. (NOT gates, of course, constitute an exception to this rule.)
        </li>
        <li>The<b class="button">Use NAND Gates Only</b> option specifies that you would like it to translate the circuit into one using only NAND gates. You can select both options if you want to use only two-input NAND gates.
        </li>
      </ul>
      <p>
        Logisim cannot construct a NAND-only circuit for an expression containing any XOR operators. This option will therefore be disabled if any outputs' expressions contain XORs.
      </p>
      <p>
        <b>Next:</b> <a href="../index.html">User's Guide</a>.
      </p>
    </div>
  </body>
</html>
